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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Central domain deletions affect the SAXS solution structure and function of Yeast Hsp40 proteins Sis1 and Ydj1

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Autor(es):
Silva, Julio C. [1, 2, 3] ; Borges, Julio C. [4] ; Cyr, Douglas M. [5] ; Ramos, Carlos H. I. [6] ; Torriani, Iris L. [2, 3]
Número total de Autores: 5
Afiliação do(s) autor(es):
[1] European Synchrotron Radiat Facil, F-38043 Grenoble - France
[2] State Univ Campinas UNICAMP, Gleb Wataghin Phys Inst, Dept Condensed Matter Phys, BR-13083859 Campinas, SP - Brazil
[3] Ctr Res Energy & Mat CNPEM, Brazilian Biosci Natl Lab, BR-13083970 Campinas, SP - Brazil
[4] Univ Sao Paulo, Inst Chem Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil
[5] Univ N Carolina, Dept Cell & Dev Biol, Chapel Hill, NC 27599 - USA
[6] Univ Campinas Unicamp, Inst Chem, Dept Organ Chem, BR-13083970 Campinas, SP - Brazil
Número total de Afiliações: 6
Tipo de documento: Artigo Científico
Fonte: BMC STRUCTURAL BIOLOGY; v. 11, OCT 19 2011.
Citações Web of Science: 14
Resumo

Background: Ydj1 and Sis1 are structurally and functionally distinct Hsp40 proteins of the yeast cytosol. Sis1 is an essential gene whereas the ydj1 gene is essential for growth at elevated temperatures and cannot complement sis1 gene deletion. Truncated polypeptides capable of complementing the sis1 gene deletion comprise the J-domain of either Sis1 or Ydj1 connected to the G/F region of Sis1 (but not Ydj1). Sis1 mutants in which the G/F was deleted but G/M maintained were capable of complementing the sis1 gene deletion. Results: To investigate the relevance of central domains on the structure and function of Ydj1 and Sis1 we prepared Sis1 constructs deleting specific domains. The mutants had decreased affinity for heated luciferase but were equally capable of stimulating ATPase activity of Hsp70. Detailed low resolution structures were obtained and the overall flexibility of Hsp40 and its mutants were assessed using SAXS methods. Deletion of either the G/M or the G/M plus CTDI domains had little impact on the quaternary structure of Sis1 analyzed by the SAXS technique. However, deletion of the ZFLR-CTDI changed the relative position of the J-domains in Ydj1 in such a way that they ended up resembling that of Sis1. The results revealed that the G/F and G/M regions are not the only flexible domains. All model structures exhibit a common clamp-like conformation. Conclusions: Our results suggest that the central domains, previously appointed as important features for substrate binding, are also relevant keeping the J-domains in their specific relative positions. The clamp-like architecture observed seems also to be favorable to the interactions of Hsp40 with Hsp70. (AU)

Processo FAPESP: 07/05001-4 - Estudos dos sistemas chaperones moleculares HSP70 e HSP90 de parasitas
Beneficiário:Julio Cesar Borges
Linha de fomento: Auxílio à Pesquisa - Apoio a Jovens Pesquisadores